The present invention relates to the improvements in mining apparatus and more particularly to improvements in roof bolting equipment.
Perhaps the single most important consideration and challenge facing miners and mining engineers since the inception of underground mining involves the need to prevent the collapsing of the overhead ceilings or roofs and side walls (xe2x80x9cribsxe2x80x9d) of mines to prevent injury to personnel and catastrophic damage to mining equipment.
Roof bolting and rib bolting are those processes which secure the ribs, side walls and roofs of mines to other stable strata. These processes are relatively slow and are the main causes for preventing mines from advancing at a faster rate.
A currently acceptable method for supporting the roof of a mine entry involves drilling holes at predetermined intervals into the ceiling and ribs and installing elongated retaining bolts in the holes. Such bolts are commonly used in connection with retaining plates and support members. Such apparatus serves to secure together thin strata or bands of rock located adjacent the ribs and roofs and prevent lateral shifting of the strata, as well as, in some instances, to anchor the strata to more massive overlying rock. The installation of retaining bolts into the roof of a mine additionally requires the use of temporary roof support cylinders to support the roof as the bolt holes are being drilled. The reader will appreciate that during the initial engagement between the temporary cylinders and the unsupported section of roof, the condition exists for causing portions of the unsupported roof to fall. Thus, it is desirable for the operation personnel to be as far away from such apparatus as practical during its initial installation.
Over the years, a variety of different types of apparatuses have been developed for installing retaining bolts into the roof and ribs of a mine. An early roof bolting drill is disclosed in U.S. Pat. No. 2,771,273 to Pond. That device comprises an electrical powered drill assembly that is adapted to be manually pulled throughout the mine. Such device offers little protection from roof falls and falling debris during bolt installation.
In an effort to increase the speed of roof bolting, one prior art track mounted roof bolting apparatus was developed, known as the REMB (rapid entry mobile bolter) and was discussed and published in World Mining Equipment April 1997 issue (published by Independent Editorial and Technical Services of the UK). The REMB provides four vertically oriented roof bolting rigs on a forward moveable and raiseable carriage and work platform which is connected to a platform mounted above a track vehicle and which remains stationary relative to the track vehicle. The roof bolting work platform is connected to the stationary platform by a passageway and a series of steps. The bolting carriage and the work platform are attached to the track vehicle by a complex parallel linkage arrangement to the front of the vehicle, so as to keep the rigs at a 90xc2x0 degree angle at all times to the tracks as carriage, work platform and the rigs move up or down. The machine also includes a rib bolt rig behind each operator, which are mounted on the lower stationary platform. The bolting rigs are in a forward position relative to the two operators.
While the REMB has improved the speed of mining, it is not fast enough for many mining applications. One reason for this is the fact that the rib bolters are positioned on the platform which is stationary relative to track vehicle, and this platform is a separate platform from the platform where the operator will control and operate the four roof bolters. This causes several difficulties. The first is that there is a risk of injury for the operators to move up and down steps on platforms, particularly when the steps and the platforms may have water falling thereon making surfaces slippery, even if expanded metal mesh is provided.
The second difficulty relates to the fact that the operators have a bolting down-time as they move from the roof bolting platform to the rib bolting platform.
The REMB also inherently requires the double handling of the consumables as the operator must move a supply of the consumables to the roof bolting platform from the storage area on the REMB, to an area accessible by the operator on the roof bolting platform. This will entail the regular walking up and down of steps to and from the roof bolting platform.
Other prior art roof bolting apparatus mount bolting rigs onto swingable booms. Such equipment however generally form crush points which are hazardous to operators.
A continuous mining machine normally includes a rotatable cutting drum that is mounted on the front end of the mining machine. As the mining machine is advanced into the seam, the cutting drum dislodges or xe2x80x9cwinsxe2x80x9d the coal from the seam. In most continuous mining machines of this type, the won material is conveyed rearwardly of the cutting drum by a longitudinally extending conveyor that may discharge into self-propelled shuttle cars or other mobile conveying apparatuses to transport the won material from the mine face. The mining machine continuously advances into the seam and, as the material is won therefrom, an xe2x80x9centryxe2x80x9d is formed in the underground seam.
While some continuous mining equipment such as that disclosed in U.S. Pat. No. 4,655,507, published and issued on Apr. 7 1987, have multiple roof bolting rigs mounted thereon, they invariably have a series of roof bolters and rib bolters mounted thereon to provide the full range of roof bolting facilities. However, such equipment can have the same disadvantages as the REMB has due to similar construction features. The continuous miners may have some four operators working to maintain the speed of roof bolting, but the use of two additional operators is a very costly solution to the speed requirements.
Other retaining bolt installation apparatuses are adapted to be affixed to a continuous mining machine for travel therewith U.S. Pat. No. 3,493,058 to Zitko and U.S. Pat. No. 4,953,914 to LaBegue disclose such devices which can be operated by personnel located on the mining machine. While such apparatus do not require the mining machine to be removed from the entry while bolts are being installed, the mining process is, nonetheless, typically interrupted during the bolting process.
In the cut and flit method of mining, a continuous miner first proceeds down one road, it must then reverse out and turn down a second road and cut that road while a specialised roof bolter bolts in the first mentioned road. The bolter and the continuous miner are continually swapping their roadway positions as the mine face moves forward. The speed of moving forward however is generally limited to the speed of inserting bolts into the ribs and roof of the mine.
The present invention provides an apparatus for installing bolts into a mine entry, said apparatus including: a frame having a forward end, a rearward end and lateral sides; at least one bolting rig operatively mounted to said forward end of said frame; at least one roof support member attached to said forward end of said frame separate from said bolting rig for selectively supporting said mine entry as bolts are installed therein; and an operator station on said frame for supporting an operator thereon during operation of said at least one roof support member.
Preferably the apparatus further includes: a pair of drive units on opposite sides of the frame for carrying and moving the frame; a pivot assembly connecting the rearward end of the frame to each of the drive units, the pivot assembly defining a pivot axis which is generally horizontal, the frame being pivotable relative to said drives about said pivot axis; the at least one bolting rig adapted to be raised and lowered by pivoting the frame relative to the drive units about the pivot axis.
The apparatus can further include in a line across it, at least one central bolting rig and at least two side bolting rigs on opposite sides of the central bolting rig, the side bolting rigs being rotatable from a generally vertical orientation through a range of intermediate orientations to a generally horizontal outwardly facing orientation which allows for both roof and rib bolting by the side bolting rigs.
Preferably the side bolting rigs are mounted on opposed laterally extendible frames, which have at least one laterally extendible telescoping cylinder for moving each said side bolting rig.
The can be included a pair of side by side central bolting rigs each of which is independently rotatable between inclined and vertical positions.
The apparatus can also include at least one removable storage container supported on said frame and at least one deck extension platform pivotally attached to at least one said lateral side of said frame and being pivotable from a first position wherein each said deck extension protrudes laterally from said corresponding lateral side and is generally coplanar therewith and a second generally upright position. The deck extension platform can be pivoted between said first position and said second position by at least one hydraulic cylinder.
The frame can have a push blade operably attached to the forward end thereof.
The bolting rig is able to rotate through a range of angles from approximately 10xc2x0 in an inward direction from vertical, through angles from the vertical to the horizontal, to approximately 20xc2x0 below the horizontal, so that the included angle in the range is approximately 120xc2x0.
An operator station can be included on said frame for supporting an operator thereon during operation of the apparatus, said operator station being located at a position remote from said at least one bolting rig to define a work area therebetween, and a planar deck member attached to said frame and covering said work area for supporting an operator thereon, with the operator station being at least 1.5 meters away from said at least one support member.
There is preferably provided a cable reel operably attached to said frame for selectively storing and paying out power cable attached between said apparatus and a power source.
At least one bolting rig can be pivotable between a generally vertical position and a generally horizontal position and wherein said bolting rig can install bolts into a rock face in either of those two positions and in any selected intermediate position therebetween.
The frame preferably carries, at its forward end, an upstanding bolting rig support wall, a guide frame being mounted to said support wall, said bolting rig being movably supported on said guide frame and adapted to be selectively moved laterally along said guide frame parallel to said support wall.
The roof support member can include a dual acting hydraulic cylinder arranged to engage the roof and floor of said entry and extend therebetween to support said entry and retain said frame in position during operation of the bolting rig.
Each bolting rig can have a control station associated therewith and is independently operable by means of said control station.